Caption: This illustration depicts a type of brain aneurysm therapy. An aneurysm is an abnormal bulging outward of one of the arteries in the brain. The rupture of an aneurysm in the brain can lead to hemorrhagic stroke, brain damage, and death. In one treatment option for an unruptured aneurysm, a tiny catheter is inserted into a large artery, usually the femoral artery, and threaded up to the brain and the affected area. Hardening compounds can then be introduced into the aneurysm, effectively blocking it off, and creating a more regulated blood flow.